Marcin Surówka  has got his PhD degree. Congratulation!

Photocatalytic Degradation of Herbicides at Titanium(IV) Oxide Modified with Metal Salts and Oxides

The doctoral thesis was focused on environmental problems related to contamination of water with herbicides: 2,4-D and 2,4,5-T. One of the most promising methods for water purification is heterogeneous photocatalysis. In this work a wide library of photocatalysts based on titanium(IV) oxide was synthetized. They were modified with different amounts (0.01-0.50%mol metal:Ti) of salts and oxides of following metals: Fe, Co, Ga, Bi, W, Mo, V and Ni. The materials were calcined at three chosen temperatures and characterised structurally and spectroscopically with XRD, UV-vis/DRS and photocurrent measurements. Their photocatalytic activity was investigated in the processes of terephthalic acid oxidation and herbicides and azure B degradation. Based on these studies the most favourable synthesis parameters were proposed: small modifier content and middle chosen calcination temperature, which result in both anatase and rutile presence in the final material. The most significant conclusion stated in this work is confirmation of indirect influence of modifiers on the photocatalytic activity of the materials. The role of modifiers is mostly observed during the photocatalyst synthesis – they influence the anatase to rutile ratio, being the main factor determining the overall photocatalytic activity of TiO₂. Therefore, such modifiers are regarded as TiO₂-synthesis-steering factors.